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  1. #1
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    Apr 2011
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    Old Trane VAV retrofit quandry

    So we are in the process of changing out all the controls in the Govt. buildings of a particular town. The third buiding we get to, happens to be the Tax building, has these old Trane VAV boxes that have the damper actuator inside in the box......it basically turns a threaded rod to move a round damper over the inlet hole and it backs away from the hole to allow air into the box. I cracked open the VAV box to see how it worked and it appears to have end switches at both ends that stop the shaft from turning at the appropriate place. There are 3 wires that leave the control board on the outside of the VAV box that go into the box to the accuator. The are labeled hot/open/close and I have verified its just 24v AC power open/power close. The end switches must be inline with its respected wire, either breaking the open wire or the close wire.

    Heres where the problem comes in......all the materials for the entire job have been bought and whoever looked at this building missed these VAV boxes. We planned on using Siemens ATEC's and we may still do that. The boxes are only HW reheat. The ATEC has 2 spare DO's we could use to stroke damper. We would have to do everything with programming. Back in the day there was only one TEC(long board) that would hold programming but now when I look at applecation 6633 on WCIS the last sub point is PPCL state (Empty/Loaded)...so this leads me to believe ATEC can now hold programming. Has anybody actaully loaded PPCL into ATEC's? We could load all the programming into our panels but if the network goes down none of the VAV's would work right. Hopefully there are some Siemens guy out there that can provide some input.

  2. #2
    Join Date
    Jan 2003
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    And unless someone has maintained them, you can bank on 25-50% of these damper setups have failed.

    Quote Originally Posted by Ray7129 View Post
    We could load all the programming into our panels but if the network goes down none of the VAV's would work right
    In this day and age, I can't think of a more miserable setup.
    Propagating the formula. http://www.noagendashow.com/

  3. #3
    Join Date
    May 2019
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    Jamestown, NY
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    Quote Originally Posted by Ray7129 View Post
    So we are in the process of changing out all the controls in the Govt. buildings of a particular town. The third buiding we get to, happens to be the Tax building, has these old Trane VAV boxes that have the damper actuator inside in the box......it basically turns a threaded rod to move a round damper over the inlet hole and it backs away from the hole to allow air into the box. I cracked open the VAV box to see how it worked and it appears to have end switches at both ends that stop the shaft from turning at the appropriate place. There are 3 wires that leave the control board on the outside of the VAV box that go into the box to the accuator. The are labeled hot/open/close and I have verified its just 24v AC power open/power close. The end switches must be inline with its respected wire, either breaking the open wire or the close wire.

    Heres where the problem comes in......all the materials for the entire job have been bought and whoever looked at this building missed these VAV boxes. We planned on using Siemens ATEC's and we may still do that. The boxes are only HW reheat. The ATEC has 2 spare DO's we could use to stroke damper. We would have to do everything with programming. Back in the day there was only one TEC(long board) that would hold programming but now when I look at applecation 6633 on WCIS the last sub point is PPCL state (Empty/Loaded)...so this leads me to believe ATEC can now hold programming. Has anybody actaully loaded PPCL into ATEC's? We could load all the programming into our panels but if the network goes down none of the VAV's would work right. Hopefully there are some Siemens guy out there that can provide some input.
    I've rebuilt these exact boxes before. We used regular TECs and rebuilt the dampers (surprisingly the parts are still available). The damper actuator still works on the TEC, you just have to set the motor timing to 300 or higher depending on the thread pitch.

    Sent from my Pixel 2 XL using Tapatalk

  4. #4
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    Jan 2003
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    USA
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    Of course, Trane prob makes a killing on the parts. Damn things constantly fail.

    Normally we try and convince the owner to retrofit them with a normal damper setup. Several companies make kits for this. 4 bolts, slide out the guts and stab on their kit that has a normal damper and new airflow pickup.
    Propagating the formula. http://www.noagendashow.com/

  5. #5
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    Apr 2011
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    Ocean Springs, MS
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    Thread Starter
    You guys wouldnt happen to have a part number on these retrofit kits? There's about 80 boxes in this building and I feel the same way......I know we will come across broken accuators. After all this is a govt. building maintained by cheap govt. maint. staff.

  6. #6
    Join Date
    May 2019
    Location
    Jamestown, NY
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    We bought the gears and motors for maybe $200 a box.

    Sent from my Pixel 2 XL using Tapatalk

  7. #7
    Join Date
    May 2019
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    Jamestown, NY
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    Not to mention only about ten percent had a bad gear and maybe half a bad motor.

    Sent from my Pixel 2 XL using Tapatalk

  8. #8
    Join Date
    May 2002
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    Baton Rouge, Louisiana
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    Quote Originally Posted by MatrixTransform View Post
    very soon it is you that will be pwned

  9. #9
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    Jan 2003
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    https://hvac-talk.com/vbb/showthread...e+vav+retrofit

    Pretty sure price also has a kit for these.
    Propagating the formula. http://www.noagendashow.com/

  10. #10
    Join Date
    Apr 2011
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    Ocean Springs, MS
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    Thread Starter
    Thanks for the replies everyone......hopefully we can talk them into spending the extra money to just retrofit the entire building.

  11. #11
    Join Date
    Mar 2010
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    Kent, WA.
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    Quote Originally Posted by Ray7129 View Post
    Thanks for the replies everyone......hopefully we can talk them into spending the extra money to just retrofit the entire building.

    tell them its money well spent. they wont have to worry about retro fitting them later. i have done hundreds of the old varicone trane boxes. i just use a titus DECV with no box and a air tight take off. a few bolts and the old actuator assembly comes out. add the ATTO with some tek screws add the DECV and your ready to go. the DECV has a flow cross built in and your into it less than 200 in parts and a couple hours of labor if access is good.

  12. #12
    Join Date
    Feb 2016
    Location
    Louisburg Kansas
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    Document the problem and fix clearly and back that up in writing each time at least 4 more times. If they instruct you to do it wrong make them tell you in writing. Organize your paper work and write a summary in case the government tries to negotiate your cost down.
    No man can be both ignorant and free.
    Thomas Jefferson

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